Apparatus for continuous blow down for boilers



Jne 30, 19.31.` L.. D. KENslG 1,812,050

APPARATUS FOR CNTINUO'US BLOW DOWN FOR BOILERS Filed Aug. 9. 1928 2 Sheets-Sheet l W fa J 1f I l w 3 June 30, 1931. L. D. KENslG 1,812,050

APPARATUS FOR CONTINUOUS BLOW DOWN FOR BOILERS Filed Aug. 9, 192s 2 sheets-sheet 2 Patented .lune 30, 1931 UNITED STATES PATENT OFFICE LOUIS D. KENSIG, OF WESTERN SPRINGS, ILLINOIS, ASSIGNOR TO NATIONAL ALUMINATE OORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS APPARATUS FOR CONTINUOUS BLOW DOWN FOR BOILEBS Application mea August* 9, 192s. serial No. 298,421.'

My invention relates to improvements in apparatus for continuous blow down of boilers and the like and has for one object to provide a new and improved blow down apparatus and process wherein the control of the amount of water blown down by a single boiler if only one is in the system or the relative amounts blown down by each of a plurality of boilers if there are a plurality in the system may be manually set for predetermined amounts and whereby means Aare provided for controlling the total blow down from the battery of boilers. Another object is to provide means whereby the make up or feed water is heated by the blow down water and means for vaporizing part of the blow down wate'r independent of the heat transfer to the make up and returning such vapor in a pure state to the boiler as part o the feed or make up water. Other ob'ects will appear from time to time throug out the specification and claims.

My invention is illustrated more or less diagrammatically in the accompanying drawings wherein- Figure 1 illustrates a :battery of boilers with heat exchanger, pre-heater and injector.

Figure 2 is a section through the heat exchanger showing manual boiler control in y elevatlon.

Figure 3 is a section through the continuous blow down control valve.

Figure 4 is a section through the constant pressure valve.

Like parts are indicated by like characters throughout.

A A1 are two of a .battery of boilers. A2 is a heat exchan' er, As is a feed water heater. A4 is a fee water pi e leading to the injector A5 and thence to t e discharge pipe A6 from which lead branches A" Aa to boilers A A1 .respectively controlled of course by the valves`A which may be turned off when the boiler is out of operation.

Discharging from each of the boilers at a oint just below the water line are blow ofiP pipes B B.l These pipes pass through variable orifice control valve B1 B1 consired orifice in position to control the amount of-water running oil from the boiler. Pipes Bs Ba lead from the variable orifice control valves to the blow oi manifold B4. This blow off. manifold is controlled by a s ring loaded adjustable continuous blow own valve BI5 and extends into. the heat exchan er tank B, there being a plurality of disc arge orifices ,B7 through which the water .from the manifold B* is discharged into the tank B6 at a number of points. Leading from the bottom of this tank is a run olf pipe B8 controlled by a constant pressure valve B9. This pipe extends into the heat exchanger tank Ba and is provided with a series of perforations B10 so as to draw .water oil' from the bottom of the tank at a number of vpoints thereby permitting free f and easy straight line iow of the hot blow ed to receive cold make up feed water from the pipe C". Straight heat exchan er tubes C are mounted in the tube sheet 2 and at their upper ends are also mounted in a tube sheet C7 which. is anged as indicated to engage a bonnet C8 which in turn communi- Cates with a hot water make u pipe C9 passing out through ythe wall of t e tank B? and leading to the feed water heater. This pipe is anged as at C1 and there is a packlng C11 to make a water and steam tight oirtwhere the pipe passes out from the It will be noted that the flange C1 and the bonnet C8 are free from contact with the inner walls ofthe v"tank B" and water may circulate about the flanges andthe Awater level in the heat exchanger tank will be above the bonnet' C8and pipe C. [D isa i'loat supported by' the water -in the vapor chamber D1 formed in that part of the tank BG above the tube sheet and above the bonnet CB and pipe C. This float D carries a valve stem Du upon which is mounted a valve D working in opposition to a seat D4 in the top D5 of the tank. The link DG guides the valve stem toward and from the seat Dt. The vapor pipe permits discharge of vapor or steam from the vapor chamber D. lVhen the water line is as shown in the figure the float is down low enough to permit opening of the valve D" and vapor can pass out through the vapor -pipe DT to be discharged into the feed water heater. It the water level in the tank B rises, the float will be lifted and close the. valve thus preventing` discharge of water through the vapor pipe.

Experience shows that dil'erent boilersy for some lreason or other require diierent rates ol blow olf, therefore the operator by testing the water in the individual boilers can ultimately arrive at a proper setting of the variable orifice control Vt'or each boiler.

If we say tor instance we have 150 pounds boiler pressure, the pressure. in the line beyond the variable orifice control will perhaps be 145 pounds. 'Ilie spring loaded blow down valve B5 may be set to control the blow otli and bring the pressure down to five or ten pounds gauge. This water flows into the heat exchanger. Most ot it passes down along the heat exchanger tubes giving up its heat to the cold iliconling leed water, passing the constant pressure valve which for instance will be set at three pounds static head. and is discharged to the sewer. Above the bonnet at the top end of the heat exchanger tank will be some of the blow off water.A The pressure in the tank will be to from two to live pounds or even less. lVhen the water at boiler pressure and temperature is discharged through the blow down valve into the heat exchanger tank at pressure but slightly above atmospheric as above indicated the sensible heat of the water is dissipated in the production ot' water vapor which 'passes ott from the blow down water into and from the vapor chamber and experience shows that the water vapor thus discharged amounts by weight to from tifteen to twenty per cent or sometimes even more oi the blow down water depending upon the boiler pressure carried, the greater the boiler pressure, the greater the percent of vapor. Thisvapor passes out. through the pipe from the vapor chamber and since it is pure steam without impurities may be, used for any lpurpose for which low pressure steanris desired as for instance for industrial purposes or for addition to the make up water.

The cold water passing in at the bottom. of the tanta: comes up through the heat exchanger tubes traveling in a direction opposite to the blow off vater, is heated bythe blow oft' water and discharged ultimately to the feed water heater in the form of partially heated water.

The heat of the blow off water is thus used in two ways in connection with the make up water. The heat is used when the pressure is reduced to cause vaporization. The vapor passes otl and 1s used. An appreclable amount of heat is thus saved and pure or distilled water is thus provided from the blow oll water, the temperature dropping from boiler temperature down to approximately 212o F. at the heat exchanger tank.

The remaining blow off vater at approximately 2120 F. passes down toward the discharge coming in contact with and surrounding the pipes containing the make up water and giving up its heat to the point Where the blow olf water as it leaves the tank is but slightly warmer than the make up water as it enters the tank.

In controlling the operation of the device the operator has the benefit of the pressure gauge E which enables him to properly adjust the variable orifice control valves and the spring loaded blow down valve to give the desired pressures. the spring loaded blow down valve comprises a housing with the hardened valve seat F, engaged by a hard cned ball F1, the ball being held against the seat by a follower F2 torced down by a spring F. This spriiig is guided by a pin Fl projecting upwardly Jfrom the follower F2 and slidable in a socket F5 in the valve stem F". The valve .stem FG terminates in a threaded plug FT which engages the spring YF so that rotation of the stem by means of the hand wheel F8 exerts a predetermined. t-ension upon the spring. Water travel through the valve is in the direction from left to right in Figures 3 and 4 and the pressure tends to unseat the ball from the seat in in the usual manner.

The arrangement of the constant pressure valve is substantially the same except that provision for adjustment need not be so convenient, there being no hand Wheel but merely a squared end F9 for a wrench so that adjustment may be made once and for all during operation.

If it is desired to use but a single boiler, the boilers may all be shut off except one and it will operate exactly inthe same manner as it' it were working with the others.

I have shown my device as applied to a stationary boiler plant where ample room is available. It might equally will be applied 35o portable, locomotive or other steam plants. Under some. conditions it might be desirable te have the heat exchanger arranged horizontally instead of vertically. It might he desirable to change the arrangement so that the make u p water encircled the pipes and the blow olf water went through them. Many other changes might be made without departing from the spirit of my invention.

As illustrated I have shown a singlev stage heat reproduction Where the Water in the heat exchanger tank is reducedintemperature to substantially 212o F. While the pressure is brought down substantially to atmospheric. If it were desired to heat the make up water to higher temperatures it would be lpossible to maintain a higher pressure in the heat exchanger tank thus maintaining -a higher temperature there and at some later stage in the operation pressure and temperature might again be reduced in a multi stage operation.

I claim: v

1. The combination with a boiler, a blowoff pipe and feed-water supply means, of a heat exchanger tank through which the blow-off and supply Water circulate, a vapor chamber in the tank wherein the pressure on the blow-off wafer is reduced, and a vapor pipe leading therefrom to the feed-water supply, a control valvefor the vapor pipe and a float adapted to operate the valve responsive to the position of the water level in the vapor chamber.

2. In a system comprising a plurality of boilers, a blow-off pipe and feed-water supply means, a heat exchanger tank through which the blow-off and supply water circulate, a vapor chamber in the tank wherein the pressure on the blow-off Water'is reduced, and a vapor pipe leading therefrom to the feed-Water supply, a plurality of variable orifice control valves one for each boiler in the system, a manifold adapted to receive blow-oil Water from all said variable orifice control valves, and an adjustable 'ing therefrom to the and an adjustable spring loaded blow-down boilers, of a blow-off valve interposed between the manifold and the heat exchanger tank, means for supplyl ing the blow-off water to and withdrawing it from the heat exchanger tank at a plurality of widely separated points and for insuring an even distribution of flow of blowoff water through the tank.

4. The combination with a plurality of ipe and a variable orifice control valve or each, a blow-off manifold to receive water from such pipes,

' heat exchanger tank throng blow-'off and supply water circulate, a vapor a spring loaded adjustable blow-down valve controlling the flow of water from such manifold.

5. The combination with a plurality of boilers, of a blow-off pipe and a variable orifice control valve for each, a blow-olf manifold to receive water from such pipes a spring loaded adjustable blow-down valve controlling the flow of water f'rom such manifold, a heat exchanger tank into which the blow-off Water is discharged and from which it is continuously Withdrawn, feed Water heating tubes contained within said tank through which the feed Water travels.

6. The combination with a plurality of boilers, of a blow-off pipe and a variable orifice control valve fo-r each, a blow-off manifold to receive water from such pipes, a spring loaded adjustable blow-down valve controlling the flow of water from such manifold, a heat exchanger tank into which the blow-off water is discharged and from which it is continuouslk withdrawn, feed water heating tubes contained within said' tank through which the feed water travels, the direction of flow of the blow-off water in the tank and the feed Water in vthe coils being'opposite.

7. The combination with a plurality of boilers, of a blow off pipe and a variable orifice control valve for each, a blow olf manifold to receive water from such pipes, a spring loaded adjustable. blow down valve controlling the How of Water from such manifold, a heat exchanger tank into which the blow off Water is discharged and from which it is continuously withdrawn, feed water heating tubes contained within said tank through which thel feed water travels, a vapor chamber in the tank above the level of the blow off water, a vapor discharge pipe leading ltherefrom and discharging into the feed supply.

8. The combination with a plurality of boilers, of a blow off pipe and a variable orifice control valve for each, a blow off manifold to receive water from such pipes, a spring loaded adjustable blow down valve controlling the flow of water from such manifold, a heat exchanger tank into which the"`blow off water is discharged and from which it is continuously withdrawn, feed water heating tubes contained within said. tank through which the feed -water travels, a vapor chamber in the tank above the level of the blow off Water, a vapor discharge pipe leading therefrom and discharging into the feed supply,'a yalve and float insuch chamber adapted to control the flow of vapor responsive to the level of water therein.

9. The combination with a boiler, a blowoff pipe and feed-Water suppl means, of a i which the chamber wherein the pressure on the blowolf water is reduced, a Valve adapted to control the discharge of vapor from the vapor chamber, and a. oat adapted to operate the valve responsive to the position of the water levelin the vapor chamber.

l0. In a system comprising a plurality of boilers, ablow-oif pipe and feed-water supply means, of a heat exchanger tank through which the blow-off and supply water circulate, a vapor chamber wherein the pressure on the blow-off water is reduced, and a vapor pipe leading therefrom to the eedwater supply, a plurality of variable orifice control valves one for each boiler in the system, a manifold adapted to receive blowoif water from all said Variable orifice control valves and discharge it to the heat exchanger tank through the blow-ofi' pipe, and an adjustable spring loaded blow-down valve interposed between the manifold and the heat exchanger tank.

1l. In a system comprising a plurality oi boilers, a blow-off pipe and feed-water supply means, of a heat exchanger tank through which the blow-off and supply water circulate in opposite directions, a vapor chamber wherein the pressure on the blow-olf `water is reduced, and a Vapor pipe leading therefrom to the feed water supply, a plurality of variable orifice control valves one for each boiler in the system, a manifold adapted to receive blow-off water from all said variable orifice control Valves and discharge it to the heat exchanger tank through the blow-oitl pipe, and an adjustable spring loaded blow-down valve interposed between the manifold and the heat exchanger tank, means for supplying the blow-off water to and withdrawing it from the heat exchanger tank at a plurality of Widely separated points and for insuring an even distribution of flow of blown-tt' water through the tank.

12. The combination with a plurality of boilers, of a blow-oil? pipe and a Variable orifice contro-l valve for each. a blow-ofiI manifold to receive water from such pipes, a spring loaded adjustable blow-down Valve controlling the flow of water from such manifold, a heat exchanger tank into which the blow-off water is discharged and from which it is continuously withdrawn.

Signed at Chicago, county of Cook, and State of Illinois, this 7th day of August,

LOUIS D. KENSIG.

Lsiaoso, 

